Door bells are in wide use at personal residences and some businesses to notify occupants about the arrival of a guest or solicitor. Door bell ringers are typically located on the outer perimeter of an exterior front door frame to a residence, where it can be easily located by a visitor. Although many door bells have been hard-wired from the switch located at the front door to the actual door bell in a hallway, entry, or the like, many modern door bell systems are being provided as wireless, battery operated devices adapted to transmit a wireless signal to a companion (or matching) receiving device that includes a speaker for electronically announcing a ring tone as notification that a visitor has arrived and is waiting outside the front door.
Referring to FIGS. 1A and 1B, both labeled as “prior art”, a modern, wireless door bell system is illustrated. A modern door bell ringer 10 is typically battery powered and can be mounted to the outer exterior of a doorway for a dwelling. The door bell ringer has a plunger switch 15 that activates a radio frequency transmitter 17 when it is pressed by a visitor. A radio frequency signal is transmitted from the door bell ringer 10 with a specific frequency, or bearing a specific code. The frequency or code is set by a code module 19. In some transmitters, the code is set by a series of dip switches, which are known in the art. The unique signal sent by the door bell ringer 10 is received by a door bell 20 located within the dwelling within hearing range of the dwelling's occupants. As shown in FIG. 1B, the door bell 20 includes a radio frequency receiver 21 adapted by a companion code module 22 adapted to recognize the unique signal transmitted by the door bell ringer 10. If the unique signal, e.g., code, is recognized, a microprocessor enables a ring tone stored in a memory 23 to be amplified 27 and announced through a speaker 29.
Although door bells have proven to be very useful to occupants of a residence as well as guests/solicitors trying to notify residents that the guest/solicitor is waiting outside the exterior door, it is possible that criminals may also be calling in order to “case”, or otherwise assess the vulnerability of and the value of contents within, a home or business. If the door bell is answered, the criminal can achieve the objective of assessing the dwelling, size up the occupants and determine whether alarms or pets are employed for security purposes. Most alarms have a “chime” feature that can make occupants aware that a door has been opened. A criminal can also hear the chime sounding when the front door is opened. A real, live dog typically barks whenever a door bell is rang. This too can be heard by a criminal with bad intent. As part of casing a home or business, the criminal is likely to pass on a dwelling that is protected by alarms or pets for just a routine burglary and look for a “softer” target.
The present inventors realize that protection of one's self and property is enhanced where barking dogs are present in a dwelling; unfortunately, it is not always convenient to own a live dog where home owners are routinely away from their residence for long periods of time, or where it is too burdensome to care for a pet. For these reasons, the present inventors have developed an electronic door bell notification and personal protection system that will enable the sounds of a barking dog shortly after the ringing of a doorbell, or by the activation of a portable, wireless transmitter.